This is not a chess playing program nor does it have any grasp of how chess pieces move.
Simply pick up and piece with a mouse down and move it to any other square.
Move a piece off the board to delete it.
Replace a lost piece by dragging one from the Piece Toolbox.

After 7. Bc1-g5 Qd8xd4 it seems White is bust as forced play follows, it is only after 12. o-o-o (castling)
that White even appears to be in the game.
Black chases another pawn with the Queen as the White King moves to a safer column
16. g2-g4 f7-f5 - Over confident, maybe but clearly trying to activate white squared Bishop.
18. Bd3-c4+ leads to 19. e4-e5 and 21. e5-e6 - a central isolated passed pawn almost has the power of a piece
By 21. Black has made five moves with the Queen. White just the one.
24. h4-h5 g6xh5 - Black really cracks under the strain, none of his pieces are near his King (e6:c7,g7 fork)
26. Ng5-f7+ and it really is all over, (mate in ten!?),
the Rook sacrifice is just the cherry on top, as a fork will always recover that piece.